Title: Single rotational level excitation of CO(<i>e</i> 3Σ−) by atomic sulfur radiation
Abstract: Direct poplulation of the v = 4, J = K = 27 level of the e 3Σ− state of 12CO has been accomplished by absorption of the 1483.039 Å SI line. Perturbations of this level by the nearby A 1Π state make this particular e 3Σ− ← X 1Σ+ transition strong. Resonance of the SI line with the e 3Σ− − X 1Σ+ transition is destroyed by substitution of 13CO for 12CO, but 13CO has a very strong resonance, with a different SI line, in the A 1Π ← X 1Σ+ system. The behavior of the observed emission intensities as a function of varying the CO and inert gas pressures indicates that collisionally induced cross-relaxation processes between the A 1Π and e 3Σ− states are extremely rapid, their frequencies being greater than gas kinetic collision frequency in the case of CO.